For a small aluminum boat, is a standard 4 cycle 9.9 hp or Bigfoot 9.9hp better? Boat is rated to 18hp. What is the difference between standard 4 cycle model and Bigfoot 4 cycle model in Mercury lineup? I found a 9.9 hp, 2000, shelf model, for $1695. Is this a good deal? Has there been any design changes between 2000 and 2002 that might effect my decision?<br />Thank you,<br />Tom